This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Objective: To investigate brain pathways involved in mate affiliation and parental motivation. Functional magnetic resonance imaging (fMRI) is carried out on awake male marmosets while being presented with isolated scents from (familiar vs. unfamiliar) adult females and infants. Specific hormones in the blood and CSF are used to correlate brain responsiveness with hormone levels. These were initial studies to determine if the magnet facilities at Medical College of Wisconsin would prove a useful Midwest site for the WNPRC marmosets. In addition, pilot data was collected for mate affiliation and parental motivation. There were some problems with the technology that caused increased body temperature in the marmosets during functional imaging. We have worked out the technology issue and now have a temperature controller (ability to increase or reduce the body temperature as needed), fiber-optic sensor, and other magnet compatible monitoring equipment. We are working on getting IACUC approval to continue these studies. This research used WNPRC Animal Services. Funding ended before this reporting period. A publication has resulted.